What is firebombing? Here's what happened at the GOP headquarters in North Carolina.

Over the weekend, the Orange County Republican Party headquarters in Hillsborough, North Carolina, was firebombed and vandalized with a spray-painted swastika and the message "Nazi Republicans, get out of town or else."

No injuries were reported as a result of the firebomb, which is not actually a bomb in the conventional sense, but rather an incendiary device.

Last night the Orange County Republican Party in NC was viciously fire bombed. #ncpol

Spray painted on the side of the OCGOP when it was fire bombed "Nazi Republicans leave town or else

A North Carolinian Republican official characterized the attack to the Associated Press as "political terrorism."

An investigation into the incident is ongoing, but authorities believe the fire began when a bottle containing a flammable substance was thrown through the window and stopped of its own accord after the fuel burnt out. Police have not named any suspects nor groups suspected in the matter.

Republican presidential candidate Donald Trump accused "animals representing Hillary Clinton," his bitter opponent in the race to the White House, of the crime.

Animals representing Hillary Clinton and Dems in North Carolina just firebombed our office in Orange County because we are winning @NCGOP

So, what is a firebomb made of?

Firebombs contain a thickened, highly flammable substance. Upon contact with the target, the firebomb explodes, spattering the flammable substance, sticking to nearby surfaces and slowly burning.

One of the more famous incendiary substances used for firebombs is Napalm, gasoline combined with a coagulant, which was used by the American military during the Vietnam War.